Firm claims it can put NFC tap-cash tech in a SIM card

And that it will still work buried in a phone's guts

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SK Telecom has announced that it will launch an NFC-capable SIM card next month, achieving something hitherto considered impossible while skipping over the need for technical explanation.

The company reckons that come October it will be able to offer SIMs with Near Field Communications capabilities built in, and is keen to sell them to any operator around the world who wants to provide proximity services without having to subsidise new handsets.

Quite how it has achieved this when so many others have failed is far from clear.

An NFC-capable SIM packs a radio and its antenna, not to mention the secure element, into SIM card form factor. Officially the electronics of a SIM should be glued to the back of the contacts - hanging in a carved void cut into the plastic, but we're assuming that SK has bent the rules slightly and filled the surrounding plastic too. If it works it would make any GSM phone instantly support proximity transactions such as Oyster card-style pay-by-wave ticketing and all the other cool things that NFC can do.

Applications running on a smart, or feature, phone could communicate with the NFC SIM using SIM Toolkit standards, while more basic handsets can let an application running on the SIM present the user with text menus that should be enough for most payment and ticketing applications.

Which is all fine and good, but the problem has always been getting the radio signal out of the SIM and into the world. The NFC standard demands that the chip is powered by the induction coil in the reader (so it works when the phone's battery is dead); it's not just a matter of getting the low-power 13.75MHz radio signal out of the phone, but also getting enough induced power in.

Even DeviceFidelity, which crams NFC functionality into a removable microSD card, admits its technology won't work if its chip is tucked deep within the handset. DeviceFidelity's kit works fine when the microSD card is only hidden behind a (plastic) door, but put it between the battery and the motherboard - where the SIM usually resides - and you're stuffed.

So significant are these problems that China Mobile flirted with dropping the NFC standard, and induced power, entirely and switching to a proprietary technology at 2.4GHz run off the phone's battery. It rustled up three million people to trial this approach.

Previous efforts to get NFC into a SIM have relied on an additional antenna, usually connected to the SIM by a thin wire running around the battery and allowing the antenna (and induction loop) to be stuck to the inside of the phone's casing.

SK Telecom eschews this method, but claims that the technology it has developed will work on any mobile phone regardless of how deeply embedded the SIM is. We've asked for a list of tested handsets, and some technical details of how they've achieved this, and will update when we hear back.

If it really works then it is an important development, and one that could spur NFC deployments in many markets, but remarkable claims require remarkable proof and we'll reserve judgement until we've seen this one working. ®